The bad news: A test of a sample of oil from the pipeline that caused the spill showed a highly hazardous level of PCBs -- 10,000 parts per million (ppm) -- at one location, DEC said. (PCBs at levels greater than 50 ppm are said to “present an unreasonable risk of injury to health.” )

What this means: The PCBs in the Basin may pose health risks to people with direct contact to the oil through swimming, wading, or fishing, or by eating fish or shellfish from the Basin. This may go on for years.

This could be bad news for the Sebago Canoe Club on Bergen Avenue, the four yacht clubs, and those who launch their canoes and kayaks from the Basin's launch sites.

It is uncertain for what this means for the Paerdegat Basin Park Preserve, 161 acres of Grassland and Salt Marsh, declared "Forever Wild," home to black- and yellow-crowned night herons, clapper rails, ducks and other wildlife.

DEC is requiring National Grid to: complete an environmental investigation and perform any additional required cleanup.

How the spill happened: National Grid decommissioned an underground gas pipeline and was pumping concrete into the pipe to plug it when the spill occurred in the early morning of Sep. 28. Oil, containing several hazardous substances, was spilled onto the ground and entered storm drains during fire department response operations. Approximately 800-1,400 gallons of oil spilled into the Basin.